Totally Tubular: A sponge's body is covered with thousands of
tiny holes called pores. The water flowing into the pores provides nutrients and oxygen. As the water flows out, it carries out the organism's waste.

Remove the outer covering of a hair curler, so that you are left with a tube with holes. Repeat this step for all 6 to 10 hair curlers.

Tape two of the hair curler tubes together, so they form a tall column. Then tape on one more hair curler.

Repeat Step 2 with the remaining hair curlers. Make the sponge columns different lengths. (Some corals can be three hair curlers long; some two hair curlers long and so on.)